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數組迴圈變數，最先想到的就是 for(var i=0;i<count;i++)這樣的方式了。
除此之外，也可以使用較簡便的forEach 方式
2. forEach 函數。Firefox 和Chrome 的Array 類型都有forEach的函數。使用如下：
<!--Add by oscar999--><!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN"><HTML><HEAD><TITLE> New Document </TITLE><META NAME="Author" CONTENT="oscar999"></HEAD><BODY><script>var arryAll = [];arryAll.push(1);arryAll.push(2);arryAll.push(3);arryAll.push(4);arryAll.forEach(function(e){alert(e);})</script></BODY></HTML>
但是以上，代碼在IE中卻無法正常工作。
因為IE的Array 沒有這個方法
alert(Array.prototype.forEach);
執行以上這句得到的是 "undefined"， 也就是說在IE 中 Array 沒有forEach的方法。
3. 讓IE相容forEach方法//Array.forEach implementation for IE support..//https://developer.mozilla.org/en/JavaScript/Reference/Global_Objects/Array/forEachif (!Array.prototype.forEach) {Array.prototype.forEach = function(callback, thisArg) {var T, k;if (this == null) {throw new TypeError(" this is null or not defined");}var O = Object(this);var len = O.length >>> 0; // Hack to convert O.length to a UInt32if ({}.toString.call(callback) != "[object Function]") {throw new TypeError(callback + " is not a function");}if (thisArg) {T = thisArg;}k = 0;while (k < len) {var kValue;if (k in O) {kValue = O[k];callback.call(T, kValue, k, O);}k++;}};}
詳細介紹可以參照：
https://developer.mozilla.org/en/JavaScript/Reference/Global_Objects/Array/forEach4. 如何跳出迴圈？
Js 此種狀況的forEach 不能使用continue, break; 可以使用如下兩種方式：
1. if 語句控制
2. return . (return true, false)
return --> 類似continue
以下例子是取出數組中2的倍數和3的倍數的數;
<!--Add by oscar999--><!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN"><HTML><HEAD><TITLE> New Document </TITLE><META NAME="Author" CONTENT="oscar999"></HEAD><BODY><script>if (!Array.prototype.forEach) {Array.prototype.forEach = function(callback, thisArg) {var T, k;if (this == null) {throw new TypeError(" this is null or not defined");}var O = Object(this);var len = O.length >>> 0; // Hack to convert O.length to a UInt32if ({}.toString.call(callback) != "[object Function]") {throw new TypeError(callback + " is not a function");}if (thisArg) {T = thisArg;}k = 0;while (k < len) {var kValue;if (k in O) {kValue = O[k];callback.call(T, kValue, k, O);}k++;}};}var arryAll = [];arryAll.push(1);arryAll.push(2);arryAll.push(3);arryAll.push(4);arryAll.push(5);var arrySpecial = [];arryAll.forEach(function(e){if(e%2==0) {arrySpecial.push(e);}else if(e%3==0) {arrySpecial.push(e);}})</script></BODY></HTML>
使用return 達到以上效果
arryAll.forEach(function(e){if(e%2==0) {arrySpecial.push(e);return;}if(e%3==0) { arrySpecial.push(e);return;}})
至於如何寫類似break 的效果，目前尚未找到比較好的辦法。
有搜尋一下，有的說return false 可以達成， 試了一下， 效果和return 和return ture 是一樣的。
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